Maxillofacial appliances fail clinically for two reasons: (1) color instability of the pigmented material, and (2) degradation of the static and dynamic physical properties. Several maxillofacial materials have demonstrated excellent color stability when exposed to accelerated aging. However, when these same materials were pigmented with available maxillofacial pigments some pigments were color stable while others were not. Many of these pigments were also toxic in tissue culture tests. Additionally, it has been shown that environmental stains are largely responsible for color changes in maxillofacial prostheses. The objectives of this current study are: (1) to determine if new maxillofacial elastomers and pigments are color stable and have favorable static and dynamic physical properties by exposing them to accelerated aging, (2) to develop a computer program which will quantitatively determine which specific pigments and elastomers, when blended together, will accurately match the patients' skin color as determined by reflectance curves of the patients' skin, and (3) to perfect techniques for removal of environmental stains from maxillofacial prostheses by using solvent extraction. For new materials and pigments and for solvent extraction of environmental stains toxicity tests will be conducted using tissue culture techniques. The results of this study will have great impact upon the field of maxillofacial prosthetics by significantly extending the life expectancy of maxillofacial prostheses.